LIQUID COOLED LIGHT EMITTING DIODE DEVICES
The present invention discloses a liquid cooled LED device, comprising a cooling module, a LED array module and a hollow outer tube. The cooling module comprises an inner tube for liquid conveyance having an outer surface and a pipe. The inner tube provides a cooling liquid to flow through. The LED array module is set on the outer surface of the inner tube for liquid conveyance, which is inserted into the hollow outer tube, and two of which are sealed by the hollow outer tube to prevent the cooling liquid from permeating into the LED array module set on the outer surface. The LED array module comprises a plurality of light emitting components which are set on the outer surface of the inner tube for liquid conveyance in an omnidirectional or a semi-omnidirectional configuration.
This application claims the benefit of the filing date of Taiwan Patent Application No. 103101122, filed Jan. 13, 2014, entitled “LIQUID COOLED LIGHT EMITTING DIODE DEVICES,” and the contents of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTIONThe present invention relates to a liquid cooled light emitting diode (LED) device, more particularly, to an omnidirectional or a semi-omnidirectional liquid cooled LED device.
BACKGROUND OF THE INVENTIONLED lamp is an environmental protecting and energy-saving lighting product, when compared to traditional lighting lamps; it has many advantages, such as low energy consumption, long lifespan, durability, etc. LED lamps convert 15% to 20% of the input electrical energy into visible light while the remaining part of the energy is converted into dissipated heat. Because the heat generating rate usually is higher than the dissipation rate, the LED junction temperature rises rapidly above the environmental temperature. At the same time, the heat loss is enhanced by changing optical properties of chip epitaxial materials and so as to accumulate to high temperature. The rising junction temperature of the LED chips decreases the luminous efficiency and lifetime of LEDs in the time course of operation. Therefore, the heat loss per unit volume is high enough as comparing with the other lighting devices. If the wasted thermal energy from the heat of the electric energy loss is not effectively dissipated, it will lead to the lower luminous efficiency and the shortened lifetime of the LED lamps greatly. Therefore, efficiently dissipating heat of LED lighting products is one of the important factors in the enhancement of lighting efficiency. Currently, most methods of heat dissipation involve using a heat sink, adding fans to force the heat to dissipate, and using a remote heat exchanger (heat pipe type) etc.
Furthermore, because of the contemporary tendency of “going green”, food safety, food mileage pollution-free, energy-saving are highly valued, the trend towards good agricultural practice is continuing, which also leads to a good perspective of the LED plant lamps for plant factory industry or greenhouse. Basically, indoor organic farming is developed to reduce the likelihood of microbial or other contamination of fresh crops, fruits and vegetables in pollution-free, controlled lighting, humidity and temperature environments according to the requirement of plant growth and growth stages in the life cycle of crops, fruits and vegetables. Therefore the market needs highly efficient LED plant lamps for controlled lighting in plant factory or greenhouse.
In terms of the applications for LED plant lamps, there is a need for adjusting different light source spectrums during different growth stages of plants and continuously providing so called “light fertilizer” to the plants in the time course of growth. Therefore effectively dissipating heat of LED plant lamps is critical. The conventional method of dissipating heat of LED lamps mainly adopts air cooling, however, a large amount of energy is consumed by the air conditioning to control the temperature of the greenhouse or plant factory and maintain the stability of the plant growth. Such conventional LED lamps use passive thermal radiation and conduction heat sink, namely by connecting aluminum, ceramic, plastic, or other material substrates as submounts, on which LED chips or device are positioned. These materials conduct the heat generated from the LED chips and radiate outward. The drawback of this approach is the requirement of maximizing the surface area of the materials in contact with the surrounding cooling medium and good thermal conducting material properties, which limit the efficiency of thermal dissipation. Other auxiliary thermal dissipation techniques use fan or liquid cooling to accelerate the dissipation efficiency of the above heat sink, since cooling flow velocity, choice of material, surface area are factors that affect the performance of the heat sink. Moreover, heat sink attachment and thermal interface materials also affect the chip temperature of the LED devices. Thermal adhesive improves the heat sink's performance by filling air gaps between the heat sink and the LED devices. The conventional air-cooled LED light source usually adds fan to enhance the heat dissipation efficiency. Due to have large surface area, the heat sink needs a large power consumption to drive the fan for forced cooling. The conventional liquid-cooled LED light sources usually are attached on an aluminum substrate as a cooling backboard to rapidly transfer the generated heat from the LED light source. The dissipated heat on the surface of the aluminum substrate is then taken away by a distributed pipeline and working fluid (e.g., water), which is forcibly convected through a pump. However, because of the conventional liquid-cooled LED light sources having a planar configuration, its light intensity pattern cannot be applied to the requirement of omnidirectional or semi-omnidirectional illumination patterns and the application of water immersion LED light sources, such as an ultraviolet immersion lamp for sewage treatment, algae growth lamp for biofuels, fishing lamp, and other immersion lighting sources.
According to the above description, one can understand that due to the conventional liquid-cooled LED light sources having a planar configuration, it cannot be applied to the requirements of omnidirectional or semi-omnidirectional illumination patterns or the application of water immersion LED light sources. Therefore, it is necessary to improve the method of cooling efficiency in order to solve the drawback of the conventional liquid-cooled LED device.
SUMMARY OF THE INVENTIONIn order to achieve the above purposes, the present invention provides a liquid cooled LED device, comprising a cooling module, a LED array module, and a hollow outer tube. The cooling module comprises an inner tube for liquid conveyance. The inner tube with an outer surface and a pipe is inserted into the hollow outer tube and used to provide a cooling liquid to flow through. The LED array module is set on the outer surface of the inner tube for providing light emission. The inner surface of the hollow outer tube covers the outer surface of the inner tube for preventing liquid permeation, and the two ends of the hollow outer tube is sealed to prohibit the cooling liquid from permeating into the LED array module set on the outer surface of the inner tube.
In addition, the LED array module comprises a plurality of light emitting components and a driving circuit. Each LED component of the LED array module comprises at least one LED chip and a lead frame. The at least one LED chip is attached on the lead frame, while the lead frame is attached on the outer surface of the inner tube by thermal adhesive and is connected to the driving circuit, wherein the plurality of light emitting components may be set on the outer surface of the inner tube in an omnidirectional or a semi-omnidirectional configuration.
Furthermore, the cooling module further comprises a piping system, a pump and a heat sink. The piping is connected to the two ends of the inner tube for liquid conveyance. The pump is connected to the piping system to pump the cooling liquid through the inner tube for transferring liquid. The heat sink is connected to the piping to cool the cooling liquid.
Compared to the prior art, the present invention provides a liquid cooled LED device that achieves the omnidirectional or semi-omnidirectional illumination pattern by using a cylindrical configuration of LED array module, which is set on the cylindrical outer surface of the inner tube.
Meanwhile, the inner surface of the hollow outer tube covers the outer surface of the inner tube, preventing liquid permeation, and the sealed two ends of the hollow outer tube, which can be applied in liquid immersion LED light sources.
In order for the purpose, characteristics and advantages of the present invention to be more clearly and easily understood, the embodiments and appended drawings thereof are discussed in the following.
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Compared to the prior art, the present invention provides a liquid cooled LED device, which provides an omnidirectional or semi-omnidirectional illumination pattern by the LED array module set on the cylindrical outer surface of the inner tube for water conveyance to achieve the heat dissipation effect. Furthermore, the invention may also use the hollow outer tube to cover the outer surface of the inner tube for water conveyance to achieve the effect of waterproofing. Therefore, the invention can be applied to plant growth lamps with an omnidirectional or semi-omnidirectional illumination pattern, while also lowering and stabilizing the temperature of a greenhouse with minimal energy consumption to keep plant growth. Moreover, the invention can be immersed directly into water; the cooling effect is achieved by flowing water through the inner tube due to convection, which can be applied to fishing lamps, sewage treatment lamps, or water immersion plant lamps. Therefore, the present invention can solve the disadvantages of conventional liquid cooled LED device, such as being unable to supply an omnidirectional or semi-omnidirectional illumination pattern and being unable to implement the LED light source in water.
With the examples and explanations mentioned above, the features and spirits of the invention are hopefully well described. More importantly, the present invention is not limited to the embodiment described herein. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the meets and bounds of the appended claims.
Claims
1. A liquid cooled LED device comprising:
- a cooling module, comprising a inner tube for liquid conveyance having an outer surface and an pipe, the pipe for providing a cooling liquid to flow through;
- a LED array module, set on the outer surface of the inner tube for liquid conveyance; and
- a hollow outer tube, for covering the outer surface of the inner tube for liquid conveyance, and two ends of the hollow outer tube sealed for preventing the cooling liquid from permeating into the LED array module set on the outer surface of the inner tube.
2. The liquid cooled LED device of claim 1, wherein the LED array module is an LED module with three wavelength pumping chips of blue wavelength, purple wavelength and ultraviolet wavelength.
3. The liquid cooled LED device of claim 1, wherein the LED array module is a LED module with a single wavelength of blue or purple or ultraviolet wavelength.
4. The liquid cooled LED device of claim 1, wherein the LED array module comprises a plurality of light emitting components and a driving circuit, each light emitting component comprises at least one LED chip and a lead frame, where the at least one LED chip is attached on the lead frame, the lead frame is attached on the outer surface of the inner tube for liquid conveyance by thermal adhesive and connected to the driving circuit.
5. The liquid cooled LED device of claim 4, wherein the plurality of light emitting components are set on the outer surface of the inner tube for liquid conveyance in an omnidirectional configuration.
6. The liquid cooled LED device of claim 4, wherein the plurality of light emitting components are set on the outer surface of the inner tube for liquid conveyance in a semi-omnidirectional configuration.
7. The liquid cooled LED device of claim 1, wherein the hollow outer tube is a hollow acrylic tube having an outer surface and an inner surface.
8. The liquid cooled LED device of claim 7, wherein the outer surface of the hollow outer tube is coated by a single layer of photocatalyst or plural stacks of photocatalyst.
9. The liquid cooled LED device of claim 7, wherein the inner surface of the hollow outer tube is coated by a phosphor resin layer with single color or multiple color phosphors.
10. The liquid cooled LED device of claim 1, wherein the cooling module further comprises a piping, a pump and a heat sink, the piping is connected to the two ends of the pipe of the inner tube for liquid conveyance, the pump is connected to the piping for pumping the cooling liquid through the inner tube for liquid conveyance and the piping, the heat sink is connected to the piping for cooling the cooling liquid, where the cooling liquid is a cooling water for generating a cooling effect by flowing through the inner tube, and the cross-sectional area of the inner tube is circular.
Type: Application
Filed: Jun 23, 2014
Publication Date: Jul 16, 2015
Inventor: Jung-Chieh Su (Taiwan)
Application Number: 14/312,053